Official VFX Sketch #20: One Circle Texture

Having left the sketches fairly open in the past, we’re going to try doubling down on some tight specifications to see what you can come up with! Sometimes when given the tightest constraints, we find the most amazing methods of achieving something incredible! Let’s get to it!

The Challenge: (create an effect with the following constraint): Using just one circle texture, create a magical fire effect. Feel free to squash, stretch, and warp across geometry as much as you want, but just one circle texture is it! The texture itself can be soft, or sharp-edged. (Edit: summarizing questions below, yes you can use particle systems, and any shader math as long as it does not input another texture.)

Submitting: Create a new topic in the “Events > 20 - One Circle Texture” category with your name in the title and the sketch number (e.g.: “Susie Stevens: Sketch #20 WIP”, and post your work! This includes any work in progress you may want to show as well as your final result. Final entries should be posted through either Vimeo, Youtube, or as a high quality GIF.


  1. Be sure to cite your sources if you are using other artists work as a base, or even taking inspiration! Remember, this is a learning platform, and is meant to be used as personal work that pushes you technically and/or artistically!
  2. All entries must be made during the current month. Assets must be newly made.
  3. Any tools/systems/workflows that pre-existed can be used.

Timeline: 1 month (February 3rd - February 28th 11:59 pm PST)

Scoring and Winners: Sketch badges will be awarded to all participants. Points will be earned based on the amount of likes/buzz your topic receives (hint: show your work in progress ;))

1st Place (most likes and buzz): 1st place VFX Sketch badge and avatar badge
2nd Place (second most likes and buzz): 2nd place VFX Sketch badge and avatar badge
All Participants (put forth a visible worthy effort): participation badge


Voting: To vote for your favorite entries, all you have to do is drop some love by clicking the like button on any of the owner’s posts within their topic during the course of the month. This is not the only factor in determining the winners but it is heavily influential in the final results. Winners will be selected by the 3rd of the following month.

As always, if you have any question feel free to ask below!

Good luck and have fun! :white_circle:


Sounds cool! Might participate in it :slight_smile:

Question, can we draw whatever in the circle texture?
And, one texture could be RGBA… so… are there any limitations on differences in those channels?


RGBA channels all need to be the same data, unless you want to fill a channel with all white or all black. You cannot draw custom shapes in any of the channels. The only “freedom” you have is to change the softness of the edges. Below are 2 examples of what you are constrained to use.:

If you were to use a soft circle like above, that is the only texture you get. If you chose to do a hard circle, that is the only texture you can use. The falloff of the softness is up to you if you choose a soft circle, but it needs to be uniform.


Thanks for the clarification.

One last question, what are we allowed to do inside a material/shader editor for the chosen engine?

This sounds like it’ll be a fun challenge, can’t wait to see what people come up with! :smiley:

Feel free to use any combo of math in a shader to manipulate the single texture! Just no manipulation with other textures.

What about node noises and SphereMask? Guess it’s a no go?

If it’s not based on a texture, feel free to use it! So sphere mask/noises that are math based are ok to use!

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The noise node has a texture sample mode (for optimisation) so that one is out. The procedural ones are fine.

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So, it has to be a texture? I can’t do this right?

Edit: ah nvm, jsut saw @Gimil’s comment


I’ll be keeping a close eye on this one! Sounds like a really cool challenge! Unfortunately I don’t have time to be in it myself.

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Dang, my first thought was to try to encode a bunch of information in the color channels, but y’all thought of that already :upside_down_face: Still, sounds like a fun challenge! I’ll see what I can come up with.

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Can we use particle systems or should the entire effect be made within one shader?

Yup, everything is good to use, as a normal game effect would be made, only constraint is that you can only input your one circular texture for your complete effect.

Hey Nate, can we have two version of the identical texture using different tiling settings? Like one clamped on X and Y, and the exact same texture with a wrapped version?

Yup! Offsetting in a shader, reapplying on itself, and any other shader math is good to use! As long as another texture isn’t involved!

Ok cool. I wasn’t sure if it would count as a second texture if it had different texture settings.

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FREEKN’ YES! :star_struck: Tis’ bout time!

Aw man… I gotta do this now. Can’t say I’ll put as much time as I would prefer, but I got to give this “VFX Puzzle” a shot.

SO! Just to make sure I understand this 'er challenge: The only -one- texture allowed. That -one- texture must be a uniform circle of either soft or hard edge. With this limitation (which essentially is a restriction of sorts on UV trickery), make a magical fire effect.

Everything else is fair game.

Question: Since a texture is not provided, when we collectively create our one texture I expect to see a subtle size diffrence. This is ok? We can make the Circle as big or small as we would like on the one texture?

Very interesting challenge! I’m going to follow very closely what people come up with.

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that’s one cool challenge!

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